Prepn. of chloro-fluoro and di:fluoro-nitro-benzene(s) - by heating a di:chloro-nitro-benzene with alkali fluoride in presence of catalyst

摘要

The prepn. of chlorofluoronitrobenzenes (I) and difluoronitrobenzenes (II) comprises heating dichloronitrobenzene (III) with an alkali fluoride with up to 2.5 wt.% total water content in the presence of a quat. ammonium and/or phosphonium salt, crown ether and/or polyethyleneglycoldimethyl ether as catalyst, to a temp. of no more than 200 deg. C. USE/ADVANTAGE - (I) and (II) are intermediatesa in the prodn. of pharmaceuticals and plant protecting agents. Neither the (III), the alkali metal fluoride nor the catalyst need to be dried before use, and there is no need to use a solvent. Yields are high.